#include <stdio.h>

#define ONE  (1<<0)
#define TWO  (1<<1)
#define TREE (1<<2)
#define FOUR (1<<3)

void PRINT(int flag)//经典位运算
{
  if(flag & ONE) printf("1\n");
  if(flag & TWO) printf("2\n");
  if(flag & TREE)printf("3\n");
  if(flag & FOUR)printf("4\n");
}

int main()
{
  fprintf(stdout,"start\n");
  PRINT(ONE);
  PRINT(TWO);
  PRINT(TREE);
  PRINT(FOUR);
  PRINT(ONE|TWO|TREE|FOUR);


  return 0;
}
